An assembly in the sense of the present disclosure comprises a sample block, a heat sink and at least one thermoelectric element. Such a sample block is configured to receive at least one and preferably a plurality of sample vessels. The thermoelectric element is designed as a thermoelectric cooler or a thermoelectric heater. A thermoelectric cooler uses the Peltier effect to create a heat flux between the junction of two different types of materials. A Peltier cooler, heater, or thermoelectric heat pump is a solid-state active heat pump which transfers heat from one side of the device to the other, depending on the direction of the current, with consumption of electrical energy. Such an instrument is also called a Peltier device, Peltier heat pump, solid state refrigerator, or thermoelectric cooler. It can be used either for heating or for cooling, although in practice the main application is cooling. In the field of the present disclosure, it is used as a temperature controller that either heats or cools the sample vessel for controlling a temperature-dependent reaction of a sample within the sample vessel. The heat sink is configured to remove excessive heat. The thermoelectric element and the heat sink allow controlled temperature cycles to be applied to a sample for polymerase chain reaction, which is thereby amplified. Particularly, the thermoelectric element and the heat sink allow the detection of a light reaction when excitation light is applied to the sample.
Particularly, standard thermoelectric elements with ceramics as a substrate are widespread and commonly used. Such thermoelectric elements are described in US 2008/0308140 A1.
Using the above-described thermoelectric element provides advantages concerning the handling within such an assembly. Nevertheless, there are still some drawbacks. Particularly, the tolerance for building openings or holes into thermoelectric elements with ceramics as a substrate is strongly limited. Mounting and fixing takes place between different thermoelectric elements resulting in a minimum distance between them. Further, said ceramics substrate is typically planar. They need to be strongly pre-stressed and assembled in a thermal sandwich using a thermal interface material. A thermal interface material is needed because their structure is very rigid. Nowadays standard thermoelectric elements further provide homogeneous power density due to fixed distances between semiconductor legs. The semiconductor legs are produced by cutting the required block sizes from a e.g. Bismuth Telluride ingot (raw material) and soldering them between two ceramic substrates with required electrical circuit layout copper plating. The process and assembly of the semiconductor blocks is mainly manual work. The finished thermoelectric element assembly always shows thermal edge-effects and corner-effects concerning homogeneity of temperature, caused by varying thermal loss due to cold neighborhood and limiting homogenization capacity of heated/cooled interface platen.
It is therefore an objective of the present disclosure to provide an assembly, an instrument for performing a temperature-dependent reaction and a method of performing a temperature-dependent reaction configured to overcome the above drawbacks and allowing an improved temperature control of the reaction.